Switch actuating mechanism



M. E. HENNING 2,020,836

SWITCH ACTUATING MECHANI SM Nov. 12, 1935.

Original Filed Nov. 30, 1931 Jaw/viz Patented Nov. 12, 1935 I UNITEDSTATES PATENT OFFICE SWITCH ACTUATING MECHANISM Malcolm E. Henning, DesMoines, Iowa, assignor to Penn Electric Switch 00., Des Moines, Iowa,

a corporation of Iowa 13 Claims.

The object of my invention is to provide a switch actuating mechanismwhich is simple, durable and comparatively inexpensive to manufacture,the present application being a division from my co-pending applicationSerial No. 577,906, filed November 30, 1931, now Patent No. 1,962,506,June 12, 1934.

A further object is to provide a switch structure in which one switch orcircuit breaker is actuated immediately upon movement of a powermechanism in one direction, the power mechanism having a lost motionconnection with the switch or circuit breaker and means being providedto cause the connection to shift to its opposite limit of movement uponfurther movement of the power mechanism before the mechanism operatesfurther to close another switch, thus causing immediate operation of thefirst switch or circuit breaker and delayed closing of the sec- 0nd one.

A further object 'is to provide a novel form of lost motion connectionto increase the time period occurring between the opening of the firstswitch or circuit breaker and the closing of the second switch by thepower mechanism.

Still another object is to provide a lost motion connection of thischaracter comprising a pin, a slot and resilient means, the slot havingrecessed ends and the resilient. means tending to retain the pin ineither of the recesses whenever it registers therewith, yet operable topermit the pin to slip out of one recess, travel the length of the slotand enter the other one upon added pressure being exerted sufficient toovercome the tension of the spring.

With these and other objects in view my invention consists in theconstruction, arrangement and combination of the various parts of mydevice, whereby the objects contemplated are at- 10 tained, ashereinafter more fully set forth, pointed out in my claims andillustrated in the accompanying drawing, in which:

Figure 1 is a front elevation of the switch structure embodying myinvention and showing the cover plate for the switch casing removed.

Figure 2 is a partial view of Figure 1 showing elements thereof in adifierent position.

Figure 3 is a view of a part of Figure 2 showing the parts in stillanother position; and

Figure 4 is a sectional view on the line 4-4 of Figure 1.

On the accompanying drawing I have used the reference numeral Hi toindicate a switch casing. A hub l2 extends therefrom in which a shaft l4is journalled. The outer end 0 he shaft has secured to it one end of abimetal temperature responsive element IS, the other end of which issecured to the hub l2.

The switch structure illustrated is designed for use as a stack switch"for controlling a fuel 5 burner. The hub I2 is extended through the wallof a chimney or the like so that the bimetal element i6 projects intothe chimney and is thus responsive to stack temperatures therein. Upon achange of temperature, the element i6 either 10 winds or unwinds and inso doing rotates a disc I8. The disc i8 is frictionally engaged with afreely rotatable disc 20, the friction being provided by a spring 22 anda washer 24 interposed between the spring and the disc 20. The disc 1520 has an arm 26 to which is pivoted the upper end of a link 28. Thelower end of the link 28 terminates in a pin 30 designed to travel in aslot 32 of an actuating element 34. The pin 30 has its terminal end bentas indicated at 36 to re- 20 tain it in the slot.

The actuating element 34 is pivoted on the pin 38. The ends of the slot32 are recessed as indicated at and 42. A spring 44 is connected withthe pins 30 and 38 for constraining the pin 30 to 25 remain in eitherthe recess 40or the recess 42 when it registers therewith, yet the pin30 can slip out of one recess andtravel the length of the slot, thendrop into the other recess when suflicient pressure is exerted toovercome the 30 tension of the spring.

The actuating element 34 carries a contact 46 adapted to cooperate witha contact 48. The lower end of the actuating element 34 is provided witha finger5li adapted to actuate a sliding bar 35 52 to move a leaf spring64 and thereby contact 54 carried by it with respect to a contact 56.The contacts 46, 48, 54 and 56 may be, on the type of switch shown,included inthe circuit of an oil burner or the like as shown in myco-pending application, referred to in the first object of thisapplication, or may be included in any other circuit to which they areadaptable.

The finger 50 is adapted to enact with the left end of the sliding bar52. The bar slides through a bracket 58 and hasan inclined portion 60 toslide along a flange 6| and thereby raise the left end of the .bar as itslides from the position of Figure 1 to the positions of Figures 2 and 3successively. By the time that the Figure 3 position is reached a corner62 of the bar 52 has been raised above the finger 50 so that the finger,upon further movement, can slip under this corher without causingfurther movement of the bar and the bar 52 is then free to be returnedtoward the left by the leaf spring 64.

The right end of the bar 52 is adapted to engage the leaf spring 64 onwhich the contact 54 is mounted. When it swings the spring 64 toward asomewhat stiffer spring 66 it separates the contacts 54 and 56 and uponthe spring 64 engaging the spring 66, more resistance is encountered bythe bar 52 so that the slight resistance of the light spring 64 willpermit the pin 30 to remain in one of the recesses of the slot 32 whileseparating the contacts 54 and 56, but the pin will shift to itsopposite limit of movement upon further movement of the link 28 due tothe increased resistance of the spring 66. Thereafter when the positionof Figure 3 is assumed the bar 52 will be returned toward the left bythe springs 66 and 64 and the contacts 54 and 56 will be reclosed.

Practical operation In the operation of my switch structure, assumingthe parts to be in the position of Figure 1, a winding up movement ofthe bimetal element I6 will cause downward movement of the link 28. Thiswill cause immediate opening of the contacts 46 and 48 and as soon asthey are open their full limit or the actuating element 34 strikes theswitch casing i 0, additional downward movement of the element 28 willcause the pin 30 to slip out of the recess 42 and travel downwardlythrough the slot 32, the friction connection between the shaft i4 andthe link 28, of course, being of sufficient value to overcome thetension of the spring 44.

When the power element I6 twists in an unwinding direction, however, amore complex sequence of events occurs. First the finger will engage thecorner 62 of the sliding bar 52 as in Figure 2, as soon as the link 28moves upwardly. This will slide the bar to open the contacts 54 and 55as shown, against the slight tension of the light spring 64.

After the position of Figure 2 is assumed, the spring 66 opposes travelof the bar 52, thus causing the pin 30 to slip out of the recess 40 uponfurther upward movement of the link 28. The pin 30 then travels upwardlythrough the slot 32 and finally comes to rest in the recess 42. Furtherupward movement of the link 28 causes the bar 52 to slide toward theright in opposition to the spring 66 until the position of Figure 3 isreached, where the left end of the bar 52 has been raised sufficientlyby the incline to cause the corner 62 to override the finger 58. Thesprings 66 and 64 then open the contacts 54 and 56 and further upwardmovement of the link 28 swings the actuating element 34 from theposition of Figure 3 to the position of Figure 1 thus closing thecontacts 46 and 48.

In the circuit described in my co-pending application, the contacts 54and 56 are included in a relay circuit while the contacts 46 and 48 areincluded in an ignition circuit. Thus the relay contacts 46 and 48 areopened so that the circuit is broken through the relay for stopping theoperation of the burner and a purging period is provided between suchopening and the re-establishment of the ignition through the contacts 46and 48 by the particular type of lost motion connection provided.

This is just one example of aninstallation in which this type of switchstructure and lost mo- An adjusting screw 68 is provided for varying thetension of the springs 64 and 66, in accordance with the requirements ofthe spring 44 and other factors.

Some changes may be made in the construction and arrangement of theparts of my device without departing from the real spirit and purpose ofmy invention, and it is my intention to cover by my claims, any modifiedforms of structure or use of mechanical equivalents, which may bereasonably included within their scope.

I claim as my invention:

1. In a switch structure, a pair of switches, an actuating elementtherefor, power mechanism for moving said actuating .element, said powermechanism having a lost motion connection with said actuating element,means constraining said lost motion connection to remain at either limitof its lost motion, said actuating element being connected with one ofsaid switches to open it when said power mechanism moves in onedirection, means opposing the actuating element to cause said lostmotion connection to shift to its other limit upon further movement ofthe power mechanism and trip means for permitting said switch to move toclosed position upon movement of said power mechanism after said lostmotion connection has so shifted and the other switch being connectedwith said actuating element to be closed thereby after the first switchhas been so closed.

2. In a switch structure, a pair of switches, an actuating elementtherefor, power mechanism for moving said actuating element, said powermechanism having a lost motion connection with said actuating element,means constraining said lost motion connection to remain at either limitof its lost motion, said actuating element being connected with one ofsaid switches to open it when said power mechanism moves in onedirection, means opposing the actuating element .to cause said lostmotion connection to shift to its other limit upon further movement ofthe power mechanism and trip means for permitting said switch to move toclosed position upon movement of said power mechanism after said lostmotion connection has so shifted, the other switch being connected withsaid actuating element to be closed thereby after the first switch hasbeen so closed and to be opened upon movement of the power mechanism inan opposite direction, movement of the second switch to open positionbeing limited whereby said lost motion connection again shifts to itsoriginal limit of movement after such opening of said second switch.

3. In a switch structure, a pair of switches, an actuating elementtherefor, power mechanism for moving said actuating element, said powermechanism having a lost motion connection with said actuating element,means constraining said lost motion connection to retain either limit ofits lost motion, said actuating element being connected with one of saidswitches to change its position when said power mechanism moves in onedirection, means opposing the actuating element to cause said lostmotion connection to shift to its other limit upon further movement ofthe power mechanism and trip means for permitting said switch to move toits other position upon movement of said power mechanism after said lostmotion connection has so shifted and the other switch being connectedwith said actuating element for having its position changed therebyafter the first switch has been moved to its other position.

4. In a switch structure, a pair of switches, an actuating elementtherefor, power mechanism for moving said actuating element, said powermechanism having a lost motion connection with said actuating element,means constraining said lost motion connection to retain either limit ofits lost motion, said actuating element being connected with one of saidswitches to change its position when said power mechanism moves in onedirection, means opposing the actuating element to cause said lostmotion connection to shift to its other limit upon further movement ofthe power mechanism and the other switch being connected with saidactuating element to be moved to one of its positions thereby after thefirst switch has been moved'to its other position.

5. In a switch structure, a pair of switches, an actuating elementtherefor, power mechanism for moving said actuating element, said powermechanism having a lost motion connection with said actuating element,means constraining said lost motion connection to retain either limit ofits lost motion, said actuating element being connected with one of saidswitches to change its position when said power mechanism moves in one'direction, means opposing the actuating element to cause said lostmotion connection to shift to its other limit upon further movement ofthe power mechanism and trip means for permitting said switch to move toits other position upon movement of said power mechanism after said lostmotion connection has so'shifted and the other switch being connectedwith said actuating element for having its position changed therebyafter the first switch has been moved to its other position, movement ofthe second switch to its other position being limited whereby said lostmotion connection again shifts to its original limit of movement aftersuch movement of said second switch.

6. In a switch structure, a pair of switches, an actuating elementtherefor, power mechanism for moving said actuating element, said powermechanism having a lost motion connection with said actuating element,means constraining said lost motion connection to retain either limit ofits lost motion, said actuating element being connected with one of saidswitches to change its position when said power mechanism moves in onedirection, means opposing the actuating element to cause said lostmotion connection to shift to its other limit upon further movement ofthe power mechanism and the other switch being connected with saidactuating element to be moved to one of its positions thereby after thefirst switch has been moved to its other position, movement of thesecond switch to its other position being limited whereby said lmtmotion connection again shifts to its original limit of movement aftersuch movement of said second switch.

7. In a switch structure, a pair of 'switches, an actuating element,power mechanism for moving said actuating element, the connectionbetween said power mechanism and said actuating element comprising aslot having recessed ends and a pin and resilient means constrainingsaid pin to remain in the recessed ends of said slot, although movabletherefrom upon the application of pressure sufllcient to overcome thetension of said spring, said actuating element being connected with oneof said switches to open it when said power mechanism moves'in onedirection, means opposing the actuating element to cause said lostmotion connection to shift to its other limit upon further movement ofthe power mechanism and trip means for permitting said switch to move toclosed position upon movement of said power mechanism after said lostmotion connection has so shifted and the other switch being .connectedwith said actuating element to be closed thereby after the first switchhas been so closed.

8. In a switch structure, a pair of switches, an actuating element,power mechanism for moving said actuating element, the connectionbetween said power mechanism and said actuating element comprising aslot having recessed ends and a pin and resilient means constrainingsaid pin to remain in the recessed ends of said slot, although movabletherefrom upon the application of pressure suflicient to overcome thetension of said spring, said actuating element being connected with oneof said switches to open it when said power mechanism moves in onedirection,

means opposing the actuating element to cause said lost motionconnection to shift to its other limit upon further movement of thepower mechanism and trip means for permitting said switch to move toclosed position upon movement of said power mechanism after said lostmotion connection has so shifted, the other switch being connected withsaid actuating element to be closed thereby after the first switch hasbeen so closed and to be opened upon movement of the power mechanism inan opposite direction, movement of the second switch to open positionbeing limited whereby said lost motion connection again shifts to itsoriginal limit of movement after such opening of said second switch.

9. In a switch structure, a pair of switches, an actuating element,power mechanism for moving said actuating element, the connectionbetween said power mechanism and said actuating element comprising aslot having recessed ends and a pin and resilient means constrainingsaid pin to remain in the recessed ends of said slot, although movabletherefrom upon the application of pressure suflicient to overcome thetension of said spring, said actuating element being connected with oneof said switches to change its position when said power mechanism movesin one direction, means opposing the actuating element to cause saidlost motion connection to shift to its other limit upon further movementof the power mechanism and trip means for permitting said switch to moveto its other position upon movement of said power mechanism after saidlost motion connection has so shifted and the other switch beingconnected with said actuating element for having its position changedthereby after the first switch has been moved to its other position.

10. In a switch structure, a pair of switches, an actuating element,power mechanism for moving said actuating element, the connectionbetween said power mechanism and said actuating element comprising aslot having recessed ment to be moved to one of its positions therebyafter the first switch has been moved to its other position.

11. In a switch structure, a pair of contacts, power mechanism foractuating said contacts, an actuating element interposed between saidpower mechanism and said contacts, said actuating mechanism including alost motion connection and means constraining said lost motionconnection to remain at either limit of its lost motion, said actuatingelement being cooperable with said contacts to open the same uponinitial movement of the power mechanism and actuating element and meansto cause said lost motion connection to shift to its opposite positionand said contacts to return to their initial position upon furthermovement of said power mechanism.

12. In a switch structure, a pair of contacts, power mechanism foractuating said contacts, an actuating element interposed between saidpower mechanism and said contacts; said actuating mechanism beingconnected with said power mechanism by a pin and slot connection, theends of said slot being recessed, resilient means constraining said pinto remain in either of said recesses when it registers therewith, saidactuating element being cooperable with said contacts to open the sameupon initial movement of the power mechanism and actuating element andmeans to cause said pin and slot connection to shift to its oppositeposition and said contacts to return to their initial position uponfurther movement of said power mechanism.

13. In a switch structure, the combination of power mechanism andcontacts with a lost motion connection therebetween, means to constrainsaid lost motion to remain at either limit of its lost motion and meansto cause said lost motion connection to shift to its opposite positionafter initially moving said contacts, said means comprising a springwith which the connection engages after initially moving said contactsand which is of suiiicient tension to overcome the constraint of saidmeans for constraining the lost motion connection to remain at eitherlimit of its lost motion.

MALCOLM E. HENNING.

